PITTSBURGH (KDKA) – A watchdog group is asking for an investigation into the treatment of monkeys at the University of Pittsburgh.

The group Stop Animal Exploitation Now, or SAEN, filed an official complaint with the USDA.

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Back in August, two monkeys were strangled by their chain collars when they became entangled.

One of the animals reportedly died and the other suffered bruising.

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In another incident, a marmoset was found with a hammock clip piercing its lower jaw. That animal had to be euthanized.

The animal group also says Pitt reported one marmoset escaped, and after an injury, it had to have two fingers amputated.

The watchdog group says the reports show an “ongoing pattern of negligence and carelessness.”

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A Pitt spokesperson told the Trib that the university is committed to the highest standards of care for its research animals and says it promptly reported the incidents.